Systems and Methods for Network Routing in a Multiple Backbone Network Architecture

• US 20070086429A1
• Filed: 11/30/2006
• Published: 04/19/2007
• Est. Priority Date: 02/04/2005
• Status: Active Grant

• Current Assignee: Level 3 Communications LLC (Lumen Technologies, Inc.)
• Original Assignee: Level 3 Communications Incorporated (Lumen Technologies, Inc.)
• Inventors: Lawrence, Joseph, El-Aawar, Nassar, Alcala, Raoul, Comstedt, Niclas, Loher, Darren, White, Steven
• Granted Patent: US 8,064,467 B2
• Time in Patent Office: Days
• US Class Current: 370/351
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/60 Router architectures
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/1569 Clos switching fabrics

Abstract

Embodiments of a network architecture include a backbone node having a plurality of independent routers or switches connected in a matrix, wherein the matrix includes a plurality of stages of routers or switches, to form a node having a node switching capacity that is greater than the node switching capacity of the individual routers or switches. A method includes assigning one of a plurality of backbone networks to a destination network address, associating a next hop loopback address with the destination network address, and advertising the destination network address in combination with the next hop loopback address through the selected backbone network address.

Claims

1. A method for routing packets to a first destination network address, the method comprising:

assigning a first one of a plurality of backbone networks to the first destination network address;

associating a first next hop loopback address with the first destination network address; and

advertising the first destination network address in combination with the first next hop loopback address through the first backbone network address, whereby packets addressed to the first destination network address are routed through the first backbone network.

4. The method as recited in claim 1, further comprising:

assigning a second one of the plurality of backbone networks to a second destination network address,

associating a second next hop loopback address with the second destination network address;

advertising the second destination network address in combination with the second next hop loopback address through the second backbone network address, whereby packets addressed to the second destination network address are routed through the second backbone network.

5. The method as recited in claim 1, wherein packets addressed to the first destination network address are routed through the first backbone network to the first next hop loopback address using an Internal Gateway Protocol.

6. The method as recited in claim 1, further comprising setting an internal least cost routing metric to a provider edge site identifier

7. The method as recited in claim 4 further comprising setting an internal least cost routing metric associated with the second next hop loopback address in the second backbone network equal to a value less than another internal least cost metric associated with the first next hop loopback address in the second backbone network.

8. The method as recited in claim 4, wherein the first destination network address and the second destination network address are associated with different routes through one or more customer edge networks.

9. The method as recited in claim 4, wherein an edge router associated with the second backbone network supports two internal least cost routing protocols.

10. The method as recited in claim 9, wherein the edge router performs a first internal least cost routing process through a port on the edge router facing the second backbone network, and wherein the edge router performs a second least cost routing process through another port on the edge router facing an edge network.

11. The method as recited in claim 4, wherein the first backbone network serves as a backup network to the second backbone network.

12. A computer-readable medium having computer-executable instructions for causing a computer to perform the method recited in claim 1 for routing packets to a destination endpoint.

2. The method as recited in claim 2, further comprising associating a first community identifier representing the first backbone network with the first destination network address.

3. The method as recited in claim 3, further comprising creating a route map including an association between the first destination network address and the first next hop loopback address and an association between the first destination network address and the first community identifier.

13. A method for providing communications between provider networks, the method comprising:

for each of a plurality of communication routes through one or more provider networks.

receiving an advertisement having a network address associated with the communication route;

selecting a backbone network from a plurality of backbone networks using an external least-cost routing protocol;

associating a first next hop loopback address with the destination address, wherein the first next hop loopback address is reachable via the selected backbone network.

assigning a first cost to the next hop loopback address, wherein the first cost is less than a second cost associated with a second next hop loopback address reachable by another backbone network, and

advertising the first next hop loopback address over the plurality of backbone networks, wherein advertising includes indicating the first cost of accessing the first next hop loopback address via the selected backbone network.

14. A method comprising:

assigning a destination network address to a backbone network selected from a plurality of backbone networks using an external least cost routing protocol;

associating a next hop loopback address with the destination network address, wherein the next hop loopback address corresponds to a port on a destination provider edge device in communication with the selected backbone network; and

notifying a source provider edge device that the next hop loopback address is reachable with least cost routing via the selected backbone network.

15. The method as recited in claim 14 wherein notifying the source provider edge device comprises performing an internal least cost routing protocol between the source provider edge device and a source core router device in the selected backbone network.

16. The method as recited in claim 15, further comprising performing the internal least cost routing protocol process between the source core router device and a destination core router device to determine a cost associated with the net hop loopback address.

17. A network architecture comprising a backbone node including a plurality of independent routers or switches connected in a matrix, wherein the matrix includes a plurality of stages of routers or switches, to form a node having a node switching capacity that is greater than the node switching capacity of the individual routers or switches.

18. The network architecture as recited in claim 17>

wherein the routers or switches are connected in an N×

M IP-based CLOS matrix, wherein N>

1 is the number of stages in the matrix and M>

1 is the number of routers or switches in each stage.

19. The network architecture in claim 18, wherein traffic is directed among the routers or switches using IP or Ethernet routing protocols, and wherein traffic is load balanced using one or more load balancing techniques selected from a group consisting of equal cost load balancing, traffic engineering, or flow-based load balancing.

20. The network architecture in claim 19, wherein links are provisioned on the routers or switches in a manner that supports the traffic balancing technique performed by the node.